5a, 5l, 6a, 6l, 8a, 8l: handle out of memory, large allocations

Fixes #392.

R=rsc, r2
CC=golang-dev
https://golang.org/cl/2732042

src/cmd/5a/a.h

@@ -54,7 +54,6 @@ typedef	struct	Hist	Hist;
 #define	NSYMB		8192
 #define	BUFSIZ		8192
 #define	HISTSZ		20
-#define	NHUNK		10000
 #define	EOF		(-1)
 #define	IGN		(-2)
 #define	GETC()		((--fi.c < 0)? filbuf(): *fi.p++ & 0xff)

src/cmd/5l/l.h

@@ -276,7 +276,6 @@ enum
 
 	STRINGSZ	= 200,
 	NHASH		= 10007,
-	NHUNK		= 100000,
 	MINSIZ		= 64,
 	NENT		= 100,
 	MAXIO		= 8192,

src/cmd/6a/a.h

@@ -57,7 +57,6 @@ typedef	struct	Gen2	Gen2;
 #define	NSYMB		500
 #define	BUFSIZ		8192
 #define	HISTSZ		20
-#define	NHUNK		10000
 #define	EOF		(-1)
 #define	IGN		(-2)
 #define	GETC()		((--fi.c < 0)? filbuf(): *fi.p++ & 0xff)

src/cmd/6l/l.h

@@ -196,7 +196,6 @@ enum
 	SSUB	= 1<<8,
 
 	NHASH		= 10007,
-	NHUNK		= 100000,
 	MINSIZ		= 8,
 	STRINGSZ	= 200,
 	MINLC		= 1,

src/cmd/8a/a.h

@@ -57,7 +57,6 @@ typedef	struct	Gen2	Gen2;
 #define	NSYMB		500
 #define	BUFSIZ		8192
 #define	HISTSZ		20
-#define	NHUNK		10000
 #define	EOF		(-1)
 #define	IGN		(-2)
 #define	GETC()		((--fi.c < 0)? filbuf(): *fi.p++ & 0xff)

src/cmd/8l/l.h

@@ -190,7 +190,6 @@ enum
 	SSUB = 1<<8,	/* sub-symbol, linked from parent via ->sub list */
 
 	NHASH		= 10007,
-	NHUNK		= 100000,
 	MINSIZ		= 4,
 	STRINGSZ	= 200,
 	MINLC		= 1,

src/cmd/cc/cc.h

@@ -59,7 +59,6 @@ typedef	struct	Bits	Bits;
 typedef	struct	Dynimp	Dynimp;
 typedef	struct	Dynexp	Dynexp;
 
-#define	NHUNK		50000L
 #define	BUFSIZ		8192
 #define	NSYMB		500
 #define	NHASH		1024

src/cmd/cc/dpchk.c

@@ -399,6 +399,7 @@ dpcheck(Node *n)
 		return;
 
 	i = l->param;
+	a = nil;
 	b = n->right;
 	a = Z;
 	while(i > 0) {

src/cmd/cc/lexbody

@@ -88,47 +88,32 @@ pragincomplete(void)
 		;
 }
 
-void
-gethunk(void)
-{
-	hunk = malloc(NHUNK);
-	memset(hunk, 0, NHUNK);
-	nhunk = NHUNK;
-}
-
 void*
 alloc(int32 n)
 {
 	void *p;
 
-	while((uintptr)hunk & MAXALIGN) {
-		hunk++;
-		nhunk--;
+	p = malloc(n);
+	if(p == nil) {
+		print("alloc out of mem\n");
+		exit(1);
 	}
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
+	memset(p, 0, n);
 	return p;
 }
 
 void*
-allocn(void *p, int32 on, int32 n)
+allocn(void *p, int32 n, int32 d)
 {
-	void *q;
-
-	q = (uchar*)p + on;
-	if(q != hunk || nhunk < n) {
-		while(nhunk < on+n)
-			gethunk();
-		memmove(hunk, p, on);
-		p = hunk;
-		hunk += on;
-		nhunk -= on;
+	if(p == nil)
+		return alloc(n+d);
+	p = realloc(p, n+d);
+	if(p == nil) {
+		print("allocn out of mem\n");
+		exit(1);
 	}
-	hunk += n;
-	nhunk -= n;
+	if(d > 0)
+		memset((char*)p+n, 0, d);
 	return p;
 }